Unless otherwise indicated herein, the information described in this section is not prior art to the claims and is not admitted to be prior art by inclusion in this section.
A cellular wireless network may include a number of base stations that radiate to define wireless coverage areas, such as cells and cell sectors, in which user equipment devices (UEs) such as cell phones, tablet computers, tracking devices, embedded wireless modules, and other wirelessly equipped communication devices, can operate. In turn, each base station may be coupled with network infrastructure that provides connectivity with one or more transport networks, such as the public switched telephone network (PSTN) and/or a packet-switched network such as the Internet for instance. With this arrangement, a UE within coverage of the network may engage in air interface communication with a base station and may thereby communicate via the base station with various remote network entities or with other UEs.
In an example arrangement, the network infrastructure may include one or more packet data network gateways (PGWs) or similar components that provide connectivity with a packet-switched network so as to support various communication services. For instance, the infrastructure may include gateways that support general packet-data communications, such as general web browsing, file transfer, and the like, and/or packet-based real-time media communications such as voice over Internet Protocol (VoIP) and streaming media for instance.
A representative PGW may sit as a node on a wireless service provider's private packet-switched network and may thus provide connectivity with various application servers and other entities on that private network, and with other such entities accessible through a connection between the service provider's network and one or more other networks such as the public Internet. By way of example, such a PGW may provide connectivity with an Internet Multimedia Subsystem (IMS) platform or other session server that supports VoIP calling and/or other such media services.
When a UE first enters into the coverage of cellular wireless network, the UE engages in a process of registering or “attaching” with the network, which may trigger setup of various communication channels for the UE and/or reservation of various communication resources for the UE. For instance, upon first detecting coverage of a base station, the UE may transmit an attach request message to the base station, which the base station may forward to a network controller such as a mobility management entity (MME). Upon authenticating and authorizing the UE, the network controller may then engage in further signaling with the base station and with a serving gateway (SGW), which may in turn engage in signaling with a PGW, ultimately resulting in setup of one or more bearer connections or “bearers” each extending, via the base station, between the UE and the PGW, through which the UE can then engage in packet-data communication via the PGW.
Each bearer established for a UE may define a logical communication tunnel that includes a radio bearer portion extending between the UE and the base station, and an access bearer portion extending between the base station and the PGW via the SGW. Further, each bearer may have a designated quality of service level, which may dictate how the packet data transmission along the bearer is handled by the network. For instance, a bearer could have a relatively high quality of service level, according to which network nodes (such as the base station, SGW, and various routers) along the bearer path could be set to prioritize routing of data on the bearer over routing of data on other bearers, perhaps to guarantee a particular minimum bit rate, a particular maximum level of packet delay, and/or a particular maximum level of packet loss. Alternatively, a bearer could have a relatively low quality of service level, such as a “best efforts” service level, according to which nodes along the bearer path would simply do their best to route data of the bearer, subject to higher priority handling of other bearer traffic.
In practice, a network such as this may initially establish for a UE one or more default bearers to enable the UE to engage in certain basic communications, with each default bearer having a respective quality of service level. By way of example, the network may initially establish for the UE a default Internet bearer with a best-efforts quality of service level, for use by the UE to engage in general Internet communications such as web browsing, e-mail messaging, and the like. Further, if the UE subscribes to VoIP service or another such service that would be served by an IMS, the network may initially establish for the UE a default IMS signaling bearer with a medium quality of service level, for use by the UE to engage in session setup signaling (such as Session Initiation Protocol (SIP) signaling) with the IMS to facilitate setup of VoIP calls or the like.
Further, as the UE is served by the network, the network may establish for the UE additional bearers as needed. For example, if the UE has an IMS signaling bearer and the UE engages in signaling over that bearer with an IMS to set up a packet-based real-time media session such as a VoIP call, the network may then establish for the UE a dedicated IMS bearer with a high quality of service level, for carrying media content of the session, such as VoIP voice packets, to and from the UE. Once the dedicated IMS bearer is established, the UE may then send and receive media content of the session over that dedicated IMS bearer.